The total number of evaluated patients with androgenic alopecia will be at least 300. All patients will be further grouped as good responders or poor responders to conventional medications, such as topical minoxidil and systemic finasteride. Candidate genes potentially involved in gout and its treatment response will be selected from the published literatures; specifically, two resources of candidate genes will be selected: (i) genes which are known to directly link with androgenic alopecia, and (ii) genes are potentially implicated in particular pathways of androgen/estrogen receptors, metabolism and downstream signals, and genes involved in anti-oxidants or hair growth. The SNP genotyping will be performed by MALDI-TOF Mass Spectrometry. Data analysis will be performed by comparing SNPs allele frequency between good responder and poor responder to conventional medications of patients with androgenic alopecia and further comparing to the allele frequency of SNPs in healthy controls. A functional study will also be done to prove the genetic association.